1. Field of the Invention
The present invention relates to an acrylic resin composition and a painted-film molded resin plate using the same. In particular, the acrylic resin composition and their moldings have applications as a coating member for the body of the car, exterior car body parts, internal car body parts, etc. and a coating member for the solar cell panel.
2. Description of the Related Art
The body panel that occupies most of the external shape of the car is the important parts in appearance up to now. The resin body panel has good moldability and has the larger margin in shape than the steel plate. Also, there are social demands such as energy conservation, reduction in weight, improvement in safety, etc. In recent years, the use of the resin body plate is increased under these circumstances.
In addition, the coating member of the solar cell is required to have many properties such as transparency, weather resistance, moisture resistance, rigidity, etc. The transparent resin material represented by the glass and the fluororesin is often employed to attain such demands. More particularly, the transparent resin material is excellent in the flexibility and the impact resistance rather than the glass, and can extremely reduce the weight. Thus, there is such a tendency that the transparent resin material is employed more and more in recent years.
Since the appearance quality is important to the car body plate, it is the main current that the painting is carried out by the high-temperature baking at the same time as the steel plate. Therefore, the painting equipment for the car body plate is needed in manufacturing the car body plate and thus a large investment is needed.
Also, if the resin body panel is recycled, the step of peeling off the painted film that is cured by the heating is needed. A large investment in this step is also needed.
Recently, in order to overcome the above problem, the colored film, i.e., the painted-film is employed in place of the baking painting. These films are employed in the side molding, etc. of a part of cars.
However, when the car is washed by the automatic car washing apparatus provided to the gasoline station, etc., the surface of the painted-film is scratched by the brush of the car washing apparatus used and the dust, etc. on the car body panel. In these painted-films, the scratches are detected by the naked eye with the increase of the frequency in the use of the car washing apparatus to thus cause the displeasure in appearance.
The painted-film has a colored layer and a clear layer formed on the colored layer. In general, the thermoplastic acrylic resin is employed as this clear layer. In order to improve the scratch resistance of this acrylic resin, the improvement to increase the glass transition temperature of the acrylic resin, the method of mixing the fluororesin thereinto, or the like have been tried.
In Japanese Laid-Open Patent Publications (KOKAI) Sho 63-123469 (published in 1988) and Sho 63-120640(published in 1988), the alloy of the poly (vinylidene fluoride)/acryl is disclosed. Also, in Japanese Laid-Open Patent Publication (KOHYO) Hei 02-503077(published in 1990), the clear layer made of the alloy consisting of fluorinated polymer (poly(vinylidene fluoride)) of less than 70 wt % and the acrylic resin of less than about 50 wt % is disclosed.
However, even if these improving methods are applied, it is impossible to eliminate completely the scratch of the painted-film in washing the car. In the existing painted-films, the scratches can be visually found with the increase of the frequency in the use of the car washing apparatus to thus cause the displeasure in appearance. Especially, the existing painted-films do not arrive at the level to satisfy the performances required for the body panel such as the fender, etc.
The trial to improve the frictional resistance, the hardness, and the scratch resistance of the painted-film by mixing fine grains of the transparent inorganic compound into the acrylic resin has been carried out. But it is impossible to achieve the sufficient improvement of them by dispersing/mixing the fine grains simply.
Also, since the transparent resin material used as the coating member for the solar cell in the prior art is insufficient in the scratch resistance, the problem of scratch due to the long-term use and the cleaning is caused. The increase in scratches on the surface reduces the light transmittance. Since these scratches increase the frequency of the attachment of dirt, they cause the extreme reduction in the conversion efficiency of the solar cell. Also, the scratches formed on the transparent resin material degrade the fine view in appearance of the solar cell. In addition, if the scratches are formed on the above transparent resin material, the contamination such as the dust and the oil content in the air are ready to adhere onto the material, but it is difficult to remove such attached dirt.
It is an object of the present invention to provide an acrylic resin composition with the high scratch resistance, which is possible to be used as the clear layer of the painted-film and the coating member for the solar cell panel.
Also, it is another object of the present invention to provide a painted-film molded resin plate and the coating member for the solar cell panel using the same.
An acrylic resin composition of the present invention is characterized in that an organic silicon based compound that is able to be copolymerised with or mixed with the acryl monomer or the methacryl monomer is contained in the acrylic resin composition.
As the organic silicon based compound, there may be listed the organic silicon based compound which has the hydroxyl group at a single end of polymer compound or has the organic silicon based compound which has the double bond at a single side end or both side ends.
Also, a painted-film of the present invention is characterized in that it has the above acrylic resin composition as a clear layer.
In addition, a coating member for the solar cell panel of the present invention is characterized in that it is coated on the light receiving surface of the solar cell and has the above acrylic resin composition of the present invention as the clear layer.
According to the acrylic resin composition of the present invention, the scratch resistance is improved. Therefore, since the painted-film and the coating member for the solar cell panel using this acrylic resin composition as the clear layer suppresses generation of the scratch due to the long-term use, the adhesion of the dirt can be reduced, the damage in appearance can be prevented, and the high transmittance can be maintained.